If the macro is edited at this point (double-click in normal edit mode), both the 'Output' and 'Wiki' chechboxes are not ticked. If the checkboxes are manually ticked and the macro is submitted again, there is also no change (thus no output).

I've noticed that if in Source mode the 'false' value is manually deleted, the output is displayed properly.

Also, the checkboxes are displayed below their corresponding options (instead of being displayed inline). The identified macros that also have these issues are (may not be the complete list):